It has long been known to taper the tip of a catheter, in particular, a peripherally inserted intravenous catheter in order to ease the insertion process. It has further been found that a dual bevel formed at the catheter tip eases such insertion and greatly improves the insertion process. The first bevel is a taper of approximately 3.degree. and the second bevel is a taper of approximately 27.degree..
These tips may be formed, for example, by laser cutting as shown in U.S. Pat. No. 5,425,903, or by molding as shown in U.S. Pat. No. 4,661,300 to Daugherty.
The Daugherty patent shows a molding process in which a single step operation is used to form and clip the catheter. That is, the catheter is placed on a mandrel with the catheter material extending beyond the mandrel and this assembly is then inserted into a heated mold to form the outer surface of the catheter. The mandrel is advanced to a point where it engages the mold surface to clip the flash from the catheter in a single step.
The single step process, however, has significant disadvantages as it provides for short tool life, as both the mold and the mandrel are used as cutting devices and therefore must engage and wear upon each other. This means that during usage, the outer surface formed on the catheter varies as the contact between the mandrel and the die wears upon the inner surface of the die. Furthermore, tooling must be replaced in order to maintain a sharp edge on the mandrel to provide appropriate cutting action.